This invention relates to a concrete mold fastening device for use in conjunction with a concrete mold to hold opposite and spaced mold members of the mold in a desired spaced relationship when a concrete structure is to be formed in the cavity defined between the mold members and more particularly, to a concrete mold fastening device of the above type which essentially comprises a separator and a pair of holders detachably mounted on the opposite end portions of the separator to be selectively permanently embedded in or removed out of the concrete structure as desired after the concrete structure has cured.
Generally, when a concrete structure is formed on a construction site, a separator in the form of an elongated bar is passed through opposite and spaced mold members which define a cavity therebetween for placing concrete until the opposite threaded extreme ends thereof protrude outwardly of the mold members, a pair of holders having a U-shaped cross-section are mounted on the opposite end portions of the separator inwardly of the mold members, pipes are applied against the outer surfaces of the mold members surrounding the protruding threaded extreme ends of the separator, holed retaining members are received on the protruding extreme ends of the separator by means of the holes in the retaining members until the retaining members abut against the pipes to hold the mold members in a desired spaced relationship in cooperation with the holders and pipes, concrete is placed into the cavity to form a concrete structure, the mold members, holders, pipes and retaining members are removed from the concrete structure after the concrete structure has cured and the cavities left in the surfaces of the concrete structure as the result of the removal of the holders are filled with finish mortar to give a pleasing appearance to the concrete structure surfaces. Alternatively, the holders are permanently retained on the separator within the cured concrete structure and plugs are inserted into the cavities of the holders.
However, in the conventional concrete mold fastening device of the above type, different types of holders have to be designed and manufactured for the system in which the holders are removed out of the concrete structure and the cavities in the concrete structure are filled with finish mortar and for the system in which the holders are permanently embedded in the concrete structure and the plugs are inserted into the holders, respectively. Thus, the conventional concrete mold fastening device has the disadvantages that the holders generate a substantial amount of waste in material in the manufacture of the holders and a great deal of mental burden is imposed on the operator in determining which type of holders should be selected in the formation of different concrete structures.